var countdown = 60;
function settime(obj) {
    if (countdown == 0) {
        $(obj).removeAttr("disabled");
        $(obj).text("获取验证码");
        countdown = 60;
        return;
    } else {
        $(obj).attr("disabled", true);
        $(obj).text(countdown +'s'+'后重发');
        countdown--;
    }
    setTimeout(function () {
        settime(obj)
    }, 1000)
}
